Expectation Problem

[ugastat06]

I know that I have seen this question discussed on the forum, but can't remember where. If you can point me in the right direction, I'd appreciate it.

There is a joint density function that is uniform over the region R, where R is defined over 0 < r1 < 2, r1^2/2 < r2 < sqrt(2r1). Find E(R1). Ans. .9.

[Gandalf]

http://www.actuarialoutpost.com/actu...ad.php?t=88114